Abstract
The absorption spectra of Mn2+, Fe2+, and Co2+ in dihydrated halide crystals have been studied as a function of temperature and with polarized incident radiation. The Mn2+ spectrum is quite adequately explained by considering the combined effects of a tetragonally distorted cubic potential and vibrational and/or spin—orbit perturbation on the electronic levels. The data for the Fe2+ and Co2+ crystals support the existence of potential fields of symmetry lower than tetragonal.